The transfusion of whole blood or derivatives of whole blood (“blood products”) are literally the lifeblood of patients with a range of conditions from severe trauma to surgery to cancer. According to the American Red Cross, there are more than 14 million packed red blood cell (pRBC) transfusions per year in the United States with 1 in every ten admissions to US hospitals requiring a blood transfusion on average. A similar number of transfusions of other fractions of whole blood, or blood products, such as platelets, white blood cells, plasma, albumin, immunoglobulins, clotting factors and cryoprecipitate, are administered each year. The critical need for blood extends to the military, where logistics of blood transport and storage are complicated and 8% of all hospital admissions during Operation Iraqi Freedom required massive transfusions, defined as more than 10 units of blood in the first 24 hours. Whole blood and blood products will be collectively referred to herein as “blood”.
Blood has a limited life span. A typical pRBC unit has a usable life of only 42 days while platelets must be used within 5 days of donation. This, coupled with the high demand for blood, has led to periodic blood shortages. But many medical experts believe fresh blood should be used even sooner, within 2-4 weeks. Retrospective studies have implicated transfusions of “older” blood with an increased risk of non-hemolytic transfusion reactions such as fever, transfusion related acute lung injury (TRALI), transfusion associated dyspnea (TAD), allergic reactions, infection, death and other complications. In one of these studies, the risk of in-hospital death increased by 2% for each day a packed red cell unit aged. Because of this, extending the useful life of blood products and improving the quality of blood would be helpful.